IE uses the syntax filter:alpha(opacity=50), where a lower value makes
the element more transparent, while Mozilla uses -moz-opacity:0.5 where a lower value has
the same effect on transparency. The same things goes for the CSS3 valid syntax opacity:0.5;

-moz-opacity and opacity, all elements inside the styled box will also recieve the same transparency. Can't find a way to get around this.

IE will need a position:relative on the text containing layer if you want the child element not to inherit the transparency.